The answer to your question is Umm Saleem (R.A.)  She gave her son, Hadrat Anas (R.A.), to the prophet (PBUH) when he was 10 years old because she wanted her son to be a man of supreme moral excellence.

 

Alhamdullilah, i got to learn as why he was called so. Its very intresting. Just name that sahaba, i shall share that reason, insha-Allah.

 

Brother Murabit, if you are reading this thread, kindly help this member

 

I hope you are n't frightening other members. None of our members are attending

 

Here's about Hudhaifah RA

 

Because of Hudhayfah's ability to keep a secret, the Prophet, peace be on him, confided in him the names of the munafiqin. It was a weighty secret which the Prophet did not disclose to any other off his companions. He gave Hudhayfah the task of watching the movements of the munafiqin, following their activities, and shielding the Muslims from the sinister danger they represented. It was a tremendous responsibility. The munafiqin, because they acted in secrecy and because they knew all the developments and plans of the Muslims from within presented a greater threat to the community than the outright hostility of the kuffar.

 

From this time onwards. Hudhayfah was called "The Keeper of the Secret of the Messenger of Allah". Throughout his life he remained faithful to his pledge not to disclose the names of the hypocrites. After the death of the Prophet, the Khalifah often came-to him to seek his advice concerning their movements and activities but he remained tight-lipped and cautious.

Umar was only able to find out indirectly who the hypocrites were. If anyone among the Muslims died, Umar would ask:

 

"Has Hudhayfah attended his funeral prayer?"

 

If the reply was 'yes', he would perform the prayer. If the reply was 'no', he became doubtful about the person and refrained from performing the funeral prayer for him.

 

Once Umar asked Hudhayfah: "Is any of my governors a munafiq?" "One," replied Hudhayfah. "Point him out to me," ordered Umar. "That I shall not do," insisted Hudhayfah who later said that shortly after their conversation Umar dismissed the person just as if he had been guided to him.

 

This were the notes i got from a site MCS USC --- { i don't remember it exactly} But when i verified it , i got to know it from brother Abu Zaid  that  While returning from a Ghazwah, few Munafiqs tried to Martyre Prophet Mohammed PBUH. While passing through a very narrow place beneath a hill, Munafiqs decided to push a rock over Prophet, They were all masked and nobody knew who they were. But Allah SWT,revealed  names of all these Munafiqs to  Prophet Mohammed PBUH which he did not disclosed to anyone except Hudhaifah RA. This is the basic reason. However, there are many other traditions that indicate that Prophet saws  also told many other secrets to Hudhaifah RA which were  disclosed to  else like list of names of the Munafiqs, signs of doomsday etc. Though first part of the above is authentic, second part is in doubt of its authenticity . if  Hudhaifah RA is being told other secrets or not ?